This invention relates to a contactor-circuit breaker comprising poles with separable contacts, a control electromagnet to control these contacts, and a protection device associated with a tripping device.
A contactor-circuit breaker is an electrical device used to deliberately control the power supply and to break lines carrying a load such as a motor (in other words to switch this load on and off) using an electromagnet which is specific to its “contactor” part, and to automatically break the load circuit using the protection device which is specific to its “circuit breaker” part, as soon as the protection device detects an electrical fault such as a short circuit on at least one of the lines.
In this type of equipment, the electromagnet and the protection device each use a multi-pole device to act on the mobile contacts in response to a deliberate control and detection of an electrical fault, respectively. The tripping device is capable of changing from a contact closed state to a contact open state under the action of an electromagnetic tripping device, and it may be reset by a manual control device itself capable of opening and closing the contacts.
Document EP-366 519 thus describes a contactor-circuit breaker of the type mentioned above. The protection device is mainly mechanical, such that a large number of switches are necessary to cover the required range of power voltages and currents.
Document FR-2 759 489 describes a contactor-circuit breaker in which the electromagnet switches contacts both in contactor mode and in circuit breaker mode. The hybrid nature of the operation of the electromagnet and its need for fast control in circuit breaker mode then cause problems.